In daily lives, people are unwittingly exposed to surfaces contaminated with microorganisms that may cause diseases. Many studies have shown that “dangerous spots” contaminated with certain bacteria involve cross-contamination from public telephones, door handles, hospital waiting rooms and toys in day-care centers for children, hot air hand dryers, towels and sponges used in kitchens, hands of hospital staff doing routine patient care, and surfaces of kitchen counters and knives where raw meat and vegetables are mingled.
In South Korea, the occurrence of bacterial contamination in various regions has resulted in the death of children and the elderly and has caused many people to become ill. In addition, microbial contamination of food is a major problem all around the world. Salmonella, E. coli, and other food-derived bacteria are causing an uncountable number of diseases every year. Acute symptoms include nausea, vomiting, abnormal abdominal pain, diarrhea, high fever, and headache. The onset of acute symptoms is followed by chronic consequences. It may be a great help if the presence of bacteria on surfaces of kitchen counters is simply detectable, since cross-contamination may cause bacteria derived from meat, fish, and poultry to be transferred to non-cooked foods such as vegetables.
Likewise, detecting the hazardous level of microorganisms in the food processing industry is very important in maintaining home and consumer health. Thus, monitoring of bacteria is important in the food processing industry. Processing of virtually all food products, from meat packaging to cheese production, involves monitoring microbial levels to ensure the safety in supplying food products.
In particular, beer contains not only alcohol, bittern components, and carbon dioxide but also has low pH and very low oxygen concentration, thereby not providing an environment suitable for microorganisms to inhabit. However, even in these unsuitable environmental conditions, some microorganisms are detected in beer. These microorganisms are classified as harmful beer microorganisms. Such harmful beer microorganisms not only cause beer haze but also cause beer spoilage and further cause various diseases due to bacterial contamination.
The harmful consequences caused by microbial contamination are not limited to the food industry. In recent decades, there has been a drastic increase in the number of “superbugs” and it is problematic that hospitals and health communities are sources for the superbugs. Abuse of antibiotics as well as insufficient cleanliness in hospitals has brought about vancomycin-resistant enterococci and other Gram-negative bacilli, in addition to methicillin-resistant S. aureus (MRSA), and Clostridium difficile (Dancer, 2004). According to a recent BBC's report, the death toll due to MRSA is estimated to be 5,000 people per year. The article has shown that “cleanliness is a major concern that patients have and the MRSA problem is becoming more serious.”. Considering that many patients in hospitals are already immune-deficient and thus are at greater risk of being infected, risks due to malignant bacteria in a hospital environment become even more threatening.
Bacteria existing in trace amounts in various types of specimens may be identified by detecting and measuring a peptidoglycan which is a cell wall component of bacteria. A peptidoglycan is a glycoprotein polymer containing N-acetylmuramic acid or N-glycosylmuramic acid and D-amino acid, which is a component of bacterial cell walls and forms a thin layer inside outer membranes of cell walls. Therefore, detecting and measuring a peptidoglycan may be applied to stability tests for pharmaceuticals, tests for microorganisms in water and food products, and diagnosis of infectious diseases.
As an example of compositions and methods for detecting a peptidoglycan, U.S. Pat. No. 4,970,152 discloses a composition for specifically detecting a peptidoglycan by removing proteins that react with beta-1,3-glucan from a plasma fluid of silkworm larvae. However, the composition requires the addition of calcium ions to cause phenol oxidase activity to be exerted by a peptidoglycan. That is, according to U.S. Pat. No. 4,970,152, when a body fluid is collected from an insect, it is required to add calcium ions so that activation of phenol oxidase is inhibited by calcium ions to obtain a phenol oxidase composition and the composition is used to cause color development using a peptidoglycan as a substrate.
In addition, U.S. Pat. No. 5,747,277 discloses an SLP reagent, but it does not specifically react with only a peptidoglycan because it detects a beta-1,3-glucan and a peptidoglycan at the same time.
Therefore, it is urgently needed to develop a detection system capable of quickly identifying the presence of bacteria through reaction with a peptidoglycan, for quick detection and diagnosis of bacteria which may cause diseases.